University of Vermont Extension
Department of Plant and Soil Science

Winter,
Spring News Article

WHAT’S NEW IN COLEUS

Dr. Leonard Perry, Extension Professor
University of Vermont

Many gardeners know coleus--that tender annual grown in gardens for its
richly patterned and colored foliage. Yet many may not realize that in
recent years hundreds of cultivars (cultivated varieties) have been
introduced, most growing well in the sun of northern climates. In fact, for
many of these newer selections the colors get better colors in the
sun. Just keep them well watered when young. If in a good heavy
loam, plants even may survive drought quite well.

Coleus were discovered in 1853 in the mountains of Java by plant explorer
Karl Blume, and until 2006 were named for him (Coleus blumei).
With all the variations, another scientific name recognized all these
hybrids (Coleus x hybridus). Then botanists decided to change
the name to the one now used and unpronounceable by most (Solenostemon
scutellarioides).

When I was growing up and first starting to garden, I knew coleus as just a
few cultivars, grown from seeds, and planted in the shade. Many
cultivars that you buy at general garden or mass market stores are still
grown from seeds and are among the several traditional mixes of
colors. Or, you can buy seeds of these to start yourself. Examples of
these series are Carefree (compact, leaves with lobes), Rainbow (bright
color combinations), Sabre (elongated leaves), Giant Exhibition (all kinds
of colors, a Victorian heirloom), or Wizard (compact, branches well).

Specialty and complete garden stores, and some mail order sources, now sell
cultivars grown solely from cuttings. Many of these started to be
introduced in the mid 1980’s. Since coleus plants have so many color
variations in their foliage, from solids to patterns, spots, and flecks
(very tiny spots), and since they tend to make mutations or sports on their
own, these sports then can be propagated “vegetatively” by cuttings for a
new cultivar. Many of these prefer bright light to full sun for best colors.

You even can propagate your own coleus at home if you find such a variation,
or just want to enjoy them over winter indoors as did many Victorians in
that original era of coleus craziness. If you have space indoors with bright
light, you can take cuttings in late summer. Simply cut a branch about four
to six inches long, removing the lower two-thirds of the leaves.
Although many people root them just in a glass of water, I prefer a mix of
equal parts vermiculite and perlite. Keep cuttings moist with a
plastic bag covering the pot until they begin to root in a couple weeks.

If keeping coleus indoors, check regularly for mealybug pests (cottony white
masses). Give plenty of light, or place under artificial gro-lights
for 16 hours a day. If plants get leggy, simply “pinch” the top third
or so to get them to branch. Keep soil moist but not too wet.

The names alone of some of the new cultivars are fun and often quite
descriptive. Some are quite exotic, such as Religious Radish (dark
red, pink margins, pointed tips), Alligator Tears (green with yellow
centers), Fright Night (narrow leaves with green, white, purple), or
Pistachio Nightmare (green and some purple surrounding pink centers).

One of the popular solid colors is the dark purple, almost black leaves of
cultivars such as Othello with its ruffled edges and Black Lace with highly
cut leaves and bright green contrasts. Dark Chocolate (available from
seeds), Dark Star and Apocalypse are others. Big Blonde has solid
light yellow leaves, as does Wasabi (this one has lobed margins).

Some have a solid color with different colored edge or margin. Molton
Orange is, of course, orange but has a green edge. Garnet Robe is
garnet red with yellow scalloped leaf margins. Solar Flair is purple
with a green margin. Aurora is light pink with green margins.
Skyrocket and Big Red are red with yellow edges. Lord Voldemort is a
striking dark purple with bright green margins. The Flume is highly cut,
deep red, with green margins.

Then there are those solid colors with different vein colors. Peter’s
Wonder is bright pink with yellow veins and green between veins.
Rustic Orange is mainly dusky orange with some yellow on the
margins. Or the centers may be a different, often lighter, color
as in some already mentioned. Stained Glass is dark red with a lighter
center. Plum Frost is purple with a green center.

Some of my favorites have spots or flecks. Ella Cinders is purple with
olive spots, Coal Mine is green with purple flecks, and Freckles is
yellow-green with red spots. Peachy Keen is light orange with yellow
flecks.

There are cultivars with edges of leaves that appear cut by scissors in
various patterns. Penney (coppery) has ruffled edges, as does Black
Night (purple) and Etna (dark red). Flirtin Skirts has scalloped
edges. Tilt a Whirl, Killer Klown, and Twist and Twirl have quite
unusual rounded and furled leaves in various colors. A popular one
with narrow purple and green leaves, deeply cut, is Kiwi Fern.

Some coleus have very small leaves, often low or even trailing, as in Inky
Fingers (did you guess green with dark markings?). Trailing Queen has
bright pink centers, while Trailing Lava Rose has bright red centers, both
then surrounded by dark red and then green margins. Trailing Plum
Brocade has dark red centers surrounded by brighter pink.

Large-leafed cultivars include Atlas (dark red, green centers) and the Kong
series. The latter came out a few years ago, and now includes a half
dozen or so cultivars such as Lime Sprite, Salmon Pink, or Mosaic.
Unlike many of the newer coleus, the Kong series prefers part to full shade.

Another new series is called Under the Sea, and has such cultivars as Lion
Fish (dark purple with some pink, highly cut leaves), Bone Fish (dark pink,
cut leaves with yellow margins), and Electric Coral (highly cut leaves, dark
red with green margins).

These are only a few examples to give you an idea of the many variations
available. The International Coleus Society (linked from www.cultivar.org) is a great resource
if you want to learn more, and see samples of their 15 groups based on leaf
shapes (such as sabre, linear, twirled, egg-shaped, rounded and so forth).

Then there are online catalogs, such as the coleus specialist Rosy Dawn
Gardens (www.rosydawngardens.com)
or Glasshouse Works (www.glasshouseworks.com).
Coleus: Rainbow Foliage for Containers and Gardens, by New
Jersey grower Ray Rogers and published by Timber Press is a great resource
too. The National Garden Bureau (ngb.org) has a fact sheet on coleus,
as they named it a plant of the year for 2015.

Plan for some new coleus in this year’s garden, and in combination with
flowers of similar colors, or in contrast to solid colored leaves.
Just keep in mind that colors may vary, even change in your garden,
depending on the light intensity, fertility, and age of the plant.